1. Field of the Invention
The present invention relates to the engineering field of dynamoelectrical machines. It relates in particular to a dynamoelectrical machine.
A machine such as this is known, for example, from U.S. Pat. No. 3,949,255.
2. Brief Description of the Related Art
A large number of solutions as to how the winding bars of a generator winding can be wedged in place in the slots provided for this purpose in a stator are known from the prior art. Examples of wedge arrangements such as these can be found in U.S. Pat. No. 3,976,901 or U.S. Pat. No. 4,369,389.
Wedge arrangements with intermediate corrugated springs, such as those disclosed in the initially cited U.S. Pat. No. 3,949,255 and as illustrated in the form of a detail in FIGS. 1 and 2, have been proven in particular. As is shown in FIGS. 1 and 2, the known dynamoelectrical machines 10 have a double layer of winding bars 13, which are arranged in slots 12 (which are open at the top) in the stator 11. The slots 12 are closed by means of a system of inclined or parallel wedges, which system comprises an (upper) cover wedge 17 and a (lower) opposing wedge 15. Corrugated springs 16 composed of fiber-reinforced epoxy resin are inserted as elastic spacers between the cover wedge 17 and the opposing wedge 15. Different numbers of filling strips 14 are provided under each opposing wedge 15, in order to compensate for fluctuations in the dimensions of the winding bars.
The cover wedges 17 are provided on the sides with slits 19, which are arranged such that, when the cover wedge is inserted, they are aligned with cooling slits 18 provided in the stator laminated core, thus allowing cooling air to enter the cooling slits 18. The use of the corrugated springs 16 results in an “automatically readjusting” system. There is thus generally no need for wedging in place once again after a certain period of operation. A further advantage of this wedging system is that the cover wedge 17 does not move relative to the side walls of the slot 12 when being wedged in place.
A disadvantage of the wedging system shown in FIGS. 1 and 2 is, however, the considerable time penalty involved in production of the complete system.